<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    let number = 5;
    let square = number ** 2;

    console.log("Квадрат числа " + number + " равен: " + square);
</script>
</body>
</html>